The present invention relates generally to compound miter saws, or other power operated equipment or machinery. More particularly, the invention relates to improvements in an adjustable fence for such power-operated equipment, with the fence assembly having a fixed fence portion and a movable fence portion for selectively adjusting the gap between the fixed and movable fence portions in order to allow sufficient clearance for performing various operations on a workpiece when the equipment is in any of a number of different cutting or working modes.
Saws and other apparatuses designed for cutting or performing other working operations on a workpiece typically require a workpiece-supporting fence assembly in order to support and locate the workpiece in a proper fixed position for performing the working operation. Examples of such equipment include compound miter saws, which are adapted for allowing the user to selectively move the saw blade into any of a number or positions or modes for square cutting, miter cutting, bevel cutting, or compound cutting where a combination miter and bevel are cut. In addition, some operations, such as dado cutting or shaping operations, for example, require the use of saw blades or other cutting or working devices of different shapes or sizes to be substituted for one another in order to perform the desired operation on the workpiece, whether the workpiece is composed of wood, plastic, metal, or other materials.
In order to accommodate these widely varied working operations, the workpiece-supporting fence is frequently required to be at least partially adjustable in order to selectively vary the gap or space between a fixed and a movable portion of the workpiece-supporting fence, thus selectively providing clearance for the saw blade, cutter, or other device performing the working operation on the workpiece. If such adjustability were not provided, a relatively large permanent gap would have to be provided between portions of the fence in order to accommodate the widely varying range of movement, position, or size of the saw blade, cutter, or other working device. Thus, in order to provide adequate workpiece support when performing operations that do not require such large clearance, the above mentioned adjustable fence assemblies, having at least one movable fence portion, have frequently been provided.
In order to address the above-discussed problems associated with the provision of a fence assembly having an adjustable clearance gap, a variety of fence-adjusting arrangements have previously been provided. However, many of such prior fence-adjusting arrangements have suffered various disadvantages, including difficulty in maintaining proper alignment between the relatively movable fence portions in wide-gap positions, inconvenience in performing fence adjustment operations, the possibility of inadvertently misplacing a removable fence portion, lack of adequate support for relatively tall or thick workpieces, or other similar disadvantages. Thus, the need has arisen for an adjustable fence for compound miter saws, or other power equipment requiring fence adjustability, which overcomes these disadvantages, as well as providing improved ease of operation, economy in manufacturing, and other advantages that will become readily apparent to those skilled in the art from the discussion below.
In accordance with the present invention, an improved adjustable workpiece-supporting fence assembly includes a fixed fence portion fixedly interconnected with the base of the device in which it is employed, with the fixed fence portion being disposed on one side of the saw blade, the workpiece cutter, or other such device for performing a working operation on a workpiece. A movable fence portion is selectively and laterally movably interconnected with the frame on the opposite side of the work-performing blade or cutter and is laterally spaced from the fixed fence portion. The base or other portion of the device in one preferred form of the invention includes a fence-supporting portion fixedly disposed on the same opposite side of the blade or cutter, with a laterally-extending slot formed therein. The slot, which preferably has spaced opposite internal walls therein, is adapted to receive a laterally-extending tongue portion of the movable fence, with the tongue being slidably received within the slot for selective adjustable lateral movement of the movable fence toward and away from the fixed fence.
In such preferred embodiments of the present invention, a fixed clamping arrangement is interconnected with the fixed fence-supporting portion for releasably and clampingly urging the tongue on the movable fence portion against a first of the slot's internal walls at any of a number of adjusted positions therein. In addition, a movable clamping arrangement is fixedly interconnected with the movable fence portion for movement therewith and is adapted for releasably and clampingly urging the tongue portion against the same first internal wall of the slot at any of a number of the adjusted positions. Preferably, the fixed and movable clamping mechanisms are located to provide the greatest possible lateral spacing therebetween, and thus the maximum alignment and stability, when the movable fence portion is adjusted to a position wherein the lateral spacing or gap between the fixed and movable fence portions is at its minimum.
In order to accomplish the above arrangement, the preferred movable clamping mechanism includes a clamping plate pivotally interconnected with the movable fence portion and having an abutment portion pivotally movable into and out of clamping engagement with the second, opposite internal wall portion of the slot. Such pivotal movement of the clamping plate abutment portion into clamping engagement with the opposite internal wall portion of the slot causes a reactive force that clampingly urges the tongue portion of the movable fence against the first internal wall portion of the slot. This arrangement adjustably secures the movable fence portion at any of a number of selectively adjustable lateral positions relative to the fixed fence portion, regardless of the size of the fence clearance gap.
In addition, the preferred embodiments of the present invention also include a raised portion of the movable fence, with such raised portion being configured to interferingly engage with the saw blade assembly and guard, or other such movable work performing device, without inadvertently damaging the movable fence in order to alert the operator that the movable fence has not been properly adjusted for the workpiece cutting or forming operation being attempted. Such raised portion of the movable fence, as well as a similar raised portion of the fixed fence portion, provides a significant advantage when cutting or working thicker or taller workpieces.
Additional objects, advantages, and features of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings.